Method of making a bearing for spindles of spinning or twisting machines

ABSTRACT

In the case of a bearing for spindles of spinning or twisting machines, which contains a spindle bearing housing, a bolster, a centering tube, a pivot bearing and a step bearing sleeve, it is provided that a predetermined bearing play of the step bearing sleeve is adjusted to a desired dimension by maching the radial interior surface of the step bearing sleeve while the sleeve is already mounted in the centering tube.

BACKGROUND AND SUMMARY OF THE INVENTION

This is a continuation of application Ser. No. 365,716, filed June 14,1989 now abandoned.

The invention relates to a bearing for spindles of spinning or twistingmachines having a spindle bearing housing, which contains a bolster, acentering tube fastened to the spindle bearing housing in proximity ofthe bolster a pivot bearing and a step bearing sleeve, which is held bymeans of the centering tube and which has a predetermined bearingclearance with respect to a spindle shaft.

A bearing of the initially mentioned type is known from "Sussen/WSTTechnische Mitteilung" 233d 5,71. This bearing, which is relatively oldand has proven itself in practice, was designed for relatively heavyspindles for correspondingly large packages, As a result of improvementsof wind-up devices, which today establish yarn connections no longer bymeans of knots, but by means of yarn-like splicing points, much smallerpackages or cops than produced earlier are produced today on ringspinning machines, which operate at higher rotational speeds of, forexample, 25,000 min⁻¹ with a smaller stroke of approximately 200 mm andwhich work with ring diameters of 38 mm.

An object of the invention is to construct a bearing of the initiallymentioned type such that it is adapted in an improved manner to the highrotational speed, the smaller stroke and the smaller ring diameter.

This object is achieved in that the distance between the bolster and thepivot bearing amounts to maximally 100 mm, and in that the bearingclearance of the step bearing sleeve is adjusted at the step bearingsleeve already mounted in the centering tube.

The invention is based on the recognition that it is important for aneconomical production of a smaller bearing and a smaller spindle thatthe step bearing play in the area of the step bearing sleeve can beestablished with sufficiently narrow tolerances in an economical manner.In the case of the known bearings, because of the relatively largedistance between the pivot bearing and the bolster, a relatively largebearing play could be permitted in the area of the step bearing sleeve,without resulting in unacceptable values for the deflection of thespindle and of the package. However, when the distance is shortenedbetween the bolster and the step bearing, it becomes necessary to reducethe bearing play in the area of the step bearing sleeve, which, however,for reasons of bearing technology, must not be excluded completely. Thereduction of the step bearing play, as a result of the measuresaccording to the invention, is however not connected with an increase inmanufacturing costs because the step bearing play is established at thealready mounted step bearing sleeve by means of machining, so thattolerances of the centering tube and mounting tolerances have no effectin this case. Therefore, a machining of the step bearing sleeve can becarried out with the same precision as previously, while bearing playsof 0.01 mm and less can still be maintained.

In a further embodiment of the invention, it is provided that theinterior surface of the step bearing sleeve, which is already mounted inthe centering tube, is brought to the predetermined measurement bymachining. During this machining, for example, a machining by means of afriction tool, enlargements of the diameter of from 0.2 mm toapproximately 0.5 mm may be carried out in order to obtain the desiredbearing play.

In another embodiment of the invention, it is provided that the interiorsurface of the step bearing sleeve and the pertaining exterior surfaceof the shaft have a slightly conical shape, and that the step bearingsleeve is adjusted to the predetermined bearing play by means of anadjusting in axial direction. As a result, the desired bearing play canbe achieved by means of the axial adjusting of the step bearing sleeveto the very low values.

In another embodiment of the invention, it is provided that the stepbearing sleeve has a slightly conical exterior surface to which acorrespondingly slightly conical interior surface of the centering tubeis assigned, and that the step bearing sleeve is adjusted to thepredetermined bearing play by means of the axial shifting with radialdeformation. The slight bearing play can also be adjusted very preciselyin this manner. In the two latter cases, it is expedient for theinterior surfaces and the exterior surfaces to have a taper ration ofapproximately 1:50.

In a further embodiment of the invention, it is provided that thediameter for a spindle shaft, in the area of the bolster, amounts tomaximally 7 mm. By means of this dimensioning, the required diameter forthe roller bearing or its bearing seat is also limited so that thediameter of a wharve for a tangential belt drive, which normally is tobe arranged in this area, can also be limited. This limiting of thedrive wharve to a diameter that is as small as possible is expedient inview of the fact that no excessive belt speeds are required for thedesired high rotational speeds of the spindle.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an axial sectional view of a bearing for a ring spindleconstructed according to a preferred embodiment of the invention,enlarged to twice actual size;

FIG. 2 is an again very enlarged partial sectional view of a modifiedembodiment of the invention; and

FIG. 3 is an also very enlarged partial sectional view of anotherembodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

In FIG. 1, only the shaft 1 of a ring spindle is shown, which isarranged vertically and which, in an upper area which is not shown, isconstructed to accommodate a spinning package, i.e., a so-calledspinning cop. The shaft 1, in the area which is not shown, isnon-rotatably connected with a wharve 19 against which a belt moveswhich drives the whole spindle. In order to keep the belt speeds withinacceptable limits, and nevertheless obtain rotational speeds of 25,000min⁻¹, it is expedient to keep the diameter of the wharve 19 as small aspossible. This wharve diameter is essentially dependent on the diameter(D) of the shaft 1 and the bolster 4 constructed as a roller bearing. Inorder to achieve the desired conditions, the spindle shaft 1 isconstructed such that the diameter (D) is 7 mm or less.

Furthermore, in order to keep the masses to be rotated as small aspossible, the spindle shaft 1 is also limited with respect to itslength; i.e., the length (L) between the bolster 4 and a pivot bearing11, constructed as a ball in the embodiment according to FIG. 1, islimited to maximally 100 mm.

The bearing contains a spindle bearing housing 3, which is equipped withan external thread 17 by means of which it can be fastened to a spindlerail. A centering tube 2 is held with a press fit 6 in the spindlebearing housing 3. This centering tube 2 forms a preassembledconstructional unit with the bolster 4 and the step bearing 5. The stepbearing 5 consists of the above-mentioned ball which is used as thepivot bearing 11 and which is inserted into a fit 12 of the centeringtube 2. The end 10 of the shaft 1 supports itself in axial direction atthe pivot bearing 11.

At an axial distance to the pivot bearing 11, a step bearing sleeve 9 ispressed into the centering tube 2 and has a cylindrical inside diameterwhich maintains a bearing play of form 0.008 to 0.01 mm with respect tothe cylindrical end section of the shaft 1. The foot bearing sleeve 9,in the embodiment according to FIG. 1, had been pressed into thecentering tube 2 before its inside diameter was expanded to its finalmeasurement which determines the bearing play 20. This expanding of thebearing sleeve 9, which has already been mounted in the centering tube2, takes place preferably by means of a friction tool.

In order to render the centering tube 2 more elastically bendable, it isprovided in its upper area with notches 7 which are arranged to beoffset with respect to one another. In addition, the centering tube 2 issurrounded by a damping spiral 8, which is known per se and which isheld in its position by means of a spacing sleeve 16. The damping spiral8 operates in an oil bath. The centering tube 2, in the area above thestep bearing sleeve 9 and in the area of the end 10 of the shaft 1, isprovided with cross-bores, so that an oil lubrication is also achievedin the area of the pivot bearing 11 and of the step bearing sleeve 9.

A bottom 15 is inserted into the spindle bearing housing 3, which islocated with a stop surface 14 at a distance "a" of approximately onemillimeter opposite the end 13 of the centering tube 2 which is benttoward the inside. In the case of above-average axial loads of thecentering tube, the stop surface 14 therefore limits the axial movement.

In the embodiment according to FIG. 2, the bearing play 20 is shown inan exaggerated manner and should advantageously amount to between 0.008mm and 0.01 mm. In this construction, it is provided that the end areaof the shaft 1 is cylindrical and supports itself with a crowned end 10at a pivot bearing 211 constructed as a plate. The step bearing sleeve209 has a slightly conical outside diameter 224, to which acorresponding, slightly conical inside diameter 223 of the centeringtube 202 is assigned. The taper ratio amounts to approximately 1:50. Bymeans of an axial shifting of the step bearing sleeve 209 inserted inthe press fit with an overlapping of approximately 0.02 mm, adeformation is obtained of the centering tube 202 by means of widening,as well as of the step bearing sleeve 209 by means of compressing. Thiscompression of the step bearing sleeve 209 has the result that thebearing play 20 can be adjusted between the cylindrical exterior surface221 of the shaft 1 and the cylindrical interior surface 222 of the stepbearing sleeve 209. In this case, the adjusting advantageously takesplace in such a manner that, for the adjusting of the step bearingsleeve 209, a preferably pneumatic measuring instrument is used whichpermits an exact measuring of the inside diameter.

In the embodiment according to FIG. 3, the exterior surface 321 of theend area 301 of the shaft 1 as well as the interior surface 322 of thestep bearing sleeve 309, have a slightly conical shape, the taper ratiobeing also in the order of 1:50. The exterior surface 324 of the stepbearing sleeve 309 and the interior surface 323 of the centering tube302 are cylindrical. By means of the axial adjusting of the step bearingsleeve 309 arranged with a press fit in the centering tube 302, thebearing play 20 can be adjusted to a given value which depends on theaxial position of the step bearing sleeve 309. The adjusting takes placeby using a setting gauge or a corresponding measuring instrument.

As shown in the embodiments according to FIGS. 2 and 3, a plate is usedas the step bearing 211, 311, on which a crowned end 10, 310 of theshaft 1 is supported. This plate is expediently supported by anadditional supporting plate which is inserted into the centering tube202, 302 which is open at the bottom. This plate may be held by aflanging of the lower edge.

As a modification of the embodiment according to FIG. 1, it is providedthat the centering tube is produced from a piece of tube; i.e., that thecentering tube will then have a smooth outside diameter. In this case,the bolster 4 is housed in a head bearing sleeve which, as in theembodiment according to FIG. 1, forms a bearing seat having an outsidediameter which correspond to the outside diameter of the spindle bearinghousing 3 and which, by means of a shoulder, projects into the spindlebearing housing 3 and is held there with a press fit corresponding topress fit 6. The centering tube 2, which will then have a smooth outercontour, will then be inserted into the head bearing sleeve and beconnected with it by means of a press fit.

Also in this case, the outer ring of the bolster is supported in axialdirection in a shoulder, similar to the embodiment according to FIG. 1,and is held by means of a flanging of the edge of the head bearingsleeve, in which case also--as in the embodiment according to FIG. 1--asealing ring may be inserted.

Although the present invention has been described and illustrated indetail, it is to be clearly understood that the dame is by wa ofillustration and example only, and is not to be taken by way oflimitation. The spirit and scope of the present invention are to belimited only by the terms of the appended claims.

What is claimed:
 1. A process for manufacturing a bearing for spindlesof spinning of twisting machines, said bearing including a spindlebearing housing, a bolster contained in the spindle bearing housing andsurrounding a bolster bearing for engagably supporting a spindle shaftat its circumference, a step pivot bearing for engagably supporting anend of a spindle shaft, a centering tube fastened to the spindle bearinghousing in proximity to the bolster and including means for holding thestep pivot bearing, said centering tube having interior surfaces, and astep bearing sleeve having interior and exterior surfaces, said sleeveis held in the centering tube and serving to radially locate a sectionof a spindle adjacent its end supported at the step pivot bearing, saidprocess comprising:mounting the step bearing sleeve in the centeringtube, and subsequently adjusting radial step bearing play of the stepbearing sleeve with respect to a spindle to be supported thereat whilethe step bearing sleeve is mounted in the centering tube by machiningradially interior surfaces of the step bearing sleeve, whereby tolerancedeviations at the centering tube and mounting tolerances for the stepbearing sleeve at the centering tube do not adversely affect the stepbearing play adjustment while permitting economical manufacture of thebearing.
 2. The process according to claim 1, wherein the distance (L)between the bolster and the step pivot bearing is no more than 100 mm.3. The process according to claim 1, wherein a taper ratio ofapproximately 1:50 is provided for the interior surfaces of thecentering tube and the exterior surfaces of the step bearing sleeve. 4.The process according to claim 1, wherein the diameter (D) for thespindle shaft in the area of the bolster amounts to maximally 7 mm. 5.The process according to claim 1, wherein the centering tube is providedwith a seat for a bearing outer ring of the bolster.
 6. The processaccording to claim 1, further comprising holding said pivot bearingaxially and radially in said centering tube.
 7. The process according toclaim 1, wherein the centering tube, in an area connected to the seat ofthe bolster, is provided with an increased wall thickness, which is heldin the spindle bearing housing by press-fitting.
 8. The processaccording to claim 7, wherein the bolster is housed in a head bearingsleeve which is connected with the centering tube by press-fitting andwhich, in turn, is held in the spindle bearing housing by press-fitting.9. The process according to claim 8, wherein the centering tube isconstructed as a preassembled constructional unit with the bolster, thepivot bearing and the step bearing sleeve.
 10. The process according toclaim 1, wherein the bolster is housed in a head bearing sleeve which isconnected with the centering tube by means of a press fit and which, inturn, is held in the spindle bearing housing by press-fitting.
 11. Theprocess according to claim 1, wherein the centering tube is constructedas a preassembled constructional unit with the bolster, the pivotbearing and the step bearing sleeve.
 12. The process according to claim1, wherein the step bearing sleeve has a slightly conical exteriorsurface to which a corresponding slightly conical interior surface ofthe centering tube is assigned.